The invention pertains to trays. More particularly, the present invention relates to a tray for packaging portions of meat and similar foods stored and presented in refrigerated conditions.
The invention relates to a tray for packaging portions of meat and similar foods stored and presented in refrigerated conditions according to the preamble of patent claim 1.
It is known to package portions of meat or poultry with the aid of plastic trays, the tray and content being wrapped in a transparent film of plastic. Such packs serve not only for storage purposes but also for presentation purposes. The content of the pack is clearly visible through the transparent film of plastic. Packs of this type are therefore often offered in refrigerated cabinets of supermarkets or the like.
The trays are usually molded from polystyrene foam by the thermoforming process. During the production process, liquid-impermeable skins are formed on the inside and outside of the tray. In order that any liquid escaping does not collect on the base of the tray, it is also known to make the foam absorbent by the formation of open-cell regions. The base of the tray is provided from the inside with a row of holes or apertures, via which liquid can penetrate into the interior of the foam layer.
If a tray of this type is inclined, there is the risk of the liquid absorbed in the base within the foam layer running to the border and escaping there. This of course has adverse effects on presentation. An escape of liquid can only be prevented if the free edge of the border is made liquid-impermeable.
If, on the other hand, the outer border is sealed, the liquid which runs via the film or the inside of the tray to the lowest-lying border is not taken up and absorbed. It collects at the low-lying border between the latter and the film and impairs the presentation of the product.
The invention is based on the object of providing a tray for packaging portions of meat or the like and similar foods stored and presented in refrigerated conditions in which absorbed liquid remains enclosed and does not run out even in an inclined position of the tray.
This object is achieved by the features of patent claim 1.
In the case of the tray according to the invention, the inside of the base has at least one channel completely surrounding a section of the surface of the base. The channel may be of any desired cross section, for example V-shaped, rectangular, with a curved bottom and straight flanks etc. What is important is that it is a closed or largely closed channel, which on account of liquid-impermeable walling can serve as a collecting channel for liquid. The channel preferably runs close to the border of the base or close to the side wall of the tray. As a result, that surface region which serves as an underlay for the content of the pack is surrounded by the channel.
The channel described provides the basis for an advantage over customary packaging trays, the base of which is provided with a number of holes or punched perforations, which are covered to a greater or lesser extent by the content of the pack, for example a piece of meat. The covered holes or punched perforations do not serve for the removal of escaped liquid. Liquid which collects on the base of the tray is only carried away and absorbed via the remaining holes or punched perforations.
In the case of the tray according to the invention, liquid runs from the section of the surface surrounded by the channel, which has a liquid-impermeable outer layer or skin, into the channel and collects there. The in fact liquid-impermeable walling of the channel is provided according to the invention with at least one aperture allowing the passage of liquid. Along the channel there is preferably a row of apertures, via which liquid can enter the liquid-absorbent layer of the base from the channel. Since the apertures are formed only in that flank of the channel which is facing the enclosed surface section, it is also only this section that serves for liquid absorption, while liquid does not penetrate into the border region of the tray from the outset. Consequently, liquid also cannot escape via the free edge. The region between the base of the tray and the bottom of the channel is liquid-impermeable due to the forming of the channel. As a result, the liquid absorbed in the surface section of the base enclosed by the channel remains enclosed, irrespective of the inclination of the tray.
It is conceivable to interrupt the channel at one or more points. Similarly, xe2x80x9cbridgesxe2x80x9d with more or less liquid-permeable regions can be formed between the bottom of the channel and the base of the tray, without significantly impairing the general effect of the channel. Such a measure may be expedient to compensate at least partially for the loss in strength of the tray caused by the channel.
According to the design of the invention, the aperture may be formed as a hole-shaped punched perforation, which is made in the skin and the layer lying thereunder, as is the case in known trays. In the latter case, however, the punched perforations are distributed over the surface of the base.
In the present description, reference is made predominantly to trays which are molded from polystyrene foam by the thermoforming process and, on account of the production process, have a liquid-impermeable skin on the inside and outside. It goes without saying, however, that the invention also applies to those trays which are made up of a plurality of layers, for example an inner absorbent layer and at least one liquid-impermeable second layer, covering the inside. It also goes without saying that not only open-cell polystyrene foam comes into consideration for the absorbent layer but also open-cell foam of other plastics or an absorbent material acting in a different way.
In order that as large a surface area of the base as possible is enclosed, another design of the invention provides that the channel is formed in the base near the side wall.
The forming of a channel in the base of a tray means of course a weakening of its strength. In order that the weakening is minimized, another design of the invention provides that the channel adopts a changing direction in its path. The channel may, for example, run in a zigzagging or meandering form. It may have the shape of a dog""s bone. In principle, a wide variety of configurations are possible.
In particular in the case of surface sections covering only part of the base, it may be advantageous according to a further design of the invention to form branch channels in the base and possibly also in the inner side wall, via which liquid can flow to the peripheral channel.
In the case of conventional trays, it is disadvantageous if the free edge of the outwardly bent border of the tray is liquid-permeable. As mentioned above, in the case of known trays this can cause the liquid to escape and collect between the border and the film. In the case of the tray according to the invention, on the other hand, a liquid-permeable border is advantageous. Liquid which collects along the film or in some other way in the free border region can then enter the side wall, which like the base contains an inner liquid-absorbent layer, via the liquid-permeable edge by capillary action.
The take-up of liquid in the border region of the tray is further improved according to one design of the invention if elevations are formed at intervals on the upper side of the outwardly bent border. The elevations or protrusions have the effect of creating a gap between the film and the border surface, via which liquid can pass more easily over the border and enter the side wall over the free edge.